Push button switch with locking feature



y 1965 w. F. DOWDLE ETAL 3,185,783

PUSH BUTTON SWITCH WITH LOCKING FEATURE Filed June 22, 1962 INVENTORS.

WALTER F flow 0L Ro E. WHEELER By 9M '2. J/dMvy ATTORNEY.

This invention relates to switch devices and has particular relation tooil-tight switch devices including one or more switches actuated inresponse to reciprocation of a push button actuator.

Switch devices including push button switch actuators have heretoforebeen employed in a variety of applications and in certain applicationsit is advantageous that such switch devices include locking meanseffective to lock a switch in a selected operating condition and toprevent movement of the push button actuator.

In the control of punch presses, for example, it is desirable to providea push button switch device including locking means movable betweeninactive and locking positions and which during movement to the lockingposition actuates a switch, and which when in the locking position,holds the switch in the actuated position and also prevents movement ofthe push button actuator. It is desirable that the locking means be keyoperated at a position which is readily accessible'to an operator, andthe looking means should include a minimum number of parts arranged soas to not add appreciably to the cost and to the space requirements ofthe switch device. It is also desirable that the switch device be ofoil-tight design with effective sealing means preventing the passage offoreign matter through openings of the device mounting frame. I

It is therefore an object of the invention to provide a push buttonswitch device of novel and improved construction including a minimumnumber of compactly arranged parts.

It is another object of the invention to provide a push button switchdevice including novel and improved means for locking a switch in aselected operating condition and at the same time preventing movement ofthe push button actuator.

It is a further object of the invention to provide a push button switchdevice including novel and improved locking means rotatable betweeninactive and locking positions and which during rotation to the lockingposition actuates a selected one of two switches, and which when in thelocking position, holds the selected switch in the actuated conditionand also prevents movement of the push button actuator.

It is still another object of the invention to provide a switch deviceas defined in the preceding paragraph which is of oil-tight design withan improved arrangement of sealing means between openings of the, devicemounting frame and parts movably mounted within the openings.

In carrying out the invention in one preferred form, a push buttonswitch device is provided including a springbiased push button mountedfor reciprocation at the front side of a mounting frame and having astem extending through an opening of the frame and carrying a switchactuating plate at the rear of the frame, the actuating plate beingmovable towards and away from operating elements of a pair of switchesmounted at the rear of the frame in response to reciprocation of thepush button.

The actuating plate includes a depending flange which slides in a slotof the frame to prevent rotation of the plate during reciprocationthereof. A sealing ring is secured within the frame opening, preferablyby staking, to closely surround the push button stem. The switchoperating elements normally are extended outwardly of United StatesPatent O the switch casings to establish normally open and normallyclosed switch conditions which are reversed when the operating elementsare displaced inwardly of the switch casings in response to depressionof the push button.

A locking means is provided including a lock member mounted at the rearof the frame for rotation between inactive and locking positions inresponse to rotation of a key-operated cylinder by an operationperformed at the front of the frame. The cylinder extends through anopening of the frame and the lock member includes a switch-actuating camportion which engages the operating element of the normally open switchduring movement of the locking member to its locking position fordisplacing the operating element and establishinga normally closedcondition of the switch. When in the locking position the lock membermaintains the normally-open switch in its actuated condition. The lockmember includes also a projection which confronts the push button platewhen the lock member is in its locking position to prevent movement ofthe push button and the push button plate toward the switch-operatingelements. A sealing ring is mounted within the cylinder-receivingopening of the frame to closely surround a part of the cylinder.

Other objects and advantages of the invention will become apparent fromthe following description taken in conjunction with the accompanyingdrawings in which:

FIG. 1 is a view in front elevation showing the push button switchdevice of the present invention mounted upon a panel or the like whichis partly broken away;

FIG. 2 is a view in section taken along the line 22 of FIG. 1 with thelock member shown in its inactive position;

FIG. 3 is a view in rear elevation of the push button switch deviceshown detached from the panel of FIG. 1; FIG. 4 is a view in sectiontaken along the line 4-4 of FIG. 3 with the lock member shown in itslocking condition; and

FIG. 5 is an exploded view with parts shown in per spective of the pushbutton switch device of FIG. 3.

Referring now to the drawings there is illustrated a push button switchdevice represented generally by the numeral 10 and incorporatingfeatures of the present invention. In general, the device 10 is adaptedfor mounting on a panel 11 or the like (FIGS. 1 and 2) and includes oneor more electric switches, there being two switches ,12 and 13in theillustrated embodiment. As will presently appear, the switches 12 and 13are operated in response reciprocation of a push button actuator 14shown in FIGS. 1, 2 and 5. A key operated locking means 15 (FIGS. 2 and5) is mounted for rotation between inactive and locking positions toactuate one of the switches 12 and 13 during its rotation to the lockingposition and is effective when in the locking position to maintain theone switch in its actuated position and to also prevent movement'of thepush button actuator 14.

More specifically, as best shown in FIG .2 the switches 12 and 13 andthe push button actuator 14 are supported by a frame 16 adapted to beattached to the front of the panel 11 in any suitable manner, such as byscrews 15, and the switches 12 and 13 are mounted at the rear of theframe 16 behind a large opening of the panel 11. Sealing rings 16'surround the screws 15 beneath the heads thereof and bear against thescrew heads and the bevelled side walls of the screw holes when thescrews 15 are tightened.

The switches 12 and 13 are attached in side-by side relation to a flatbase 17 which in turn is secured to spaced posts 18 extending from therear face of the frame 16 as by screws 19.- As best shown in FIG. 5 theswitches 12 and 13 include respectively operating elements 20 and 21which extend through an opening 22 of the base 17 toward the rear faceof the frame 15 and which are normally biased outwardly of the switchcasings to their illustrated positions to establish respectivelynormally closed and normally open operating conditions of the switches12 and 13. When the elements Ztl and 21 are displaced inwardly of theswitch casings the switch operating conditions are reversed so that theswitch 12 assumes an open condition and the switch 13 assumes a closedcondition.

In order to effect actuation of the switches 12 and 13, the push buttonactuator 14 includes a switch actuating plate 23 (FIGS. 2 and located atthe rear of the frame 16 and carried by the push button 24 which ispositioned at the front of the frame 16 and which is mounted forreciprocation by a hollow extension 25 projecting from the front of theframe 16. The plate 23 is generally L-shaped and includes a flat mainpart 26 which is adapted to engage the tips of the operating elements 29and 21 and which is normally seated in a groove 27 formed on the rearface of the frame 16. The plate 23 includes also a depending part 28adapted to slide Within a slot 29 formed in a lateral extension 30 ofthe projection 25 and opening at the rear of the frame 16. Thisarrangement prevents undesired rotation of the push button actuator 1 1during reciprocation thereof. The plate 23 is attached to the pushbutton 24 by means of a screw 31 extending through an opening 32 of thepart 26 into threaded engagement with an opening formed in the end ofstem 33 of the push button 24 which also includes a rounded head 34 forengagement by an operator.

The actuator 14 includes a coil spring 35 which surrounds the stem 33 ofthe push button and which bears against the under side of the roundedhead 34 and against a shoulder 36 (FIGS. 2 and 5) formed within thehollow of the projection 25 so that when the actuator 14 is assembledand associated with the frame 16, the spring 35 urges the push button 24outwardly. When the push button 24 is depressed, the spring 35 iscompressed within the opening 37 of the projection 25 and the stem 33slides within a smaller opening 38 within the projection 25 to move thepart 26 of the plate 23 against the operating elements 20 and 21 of theswitches 12 and 13. When the push button 24 is released, the spring 35expands to move the push button outwardly and to move the plate 23 awayfrom the elements 20 and 21 and into the groove 27 on the rear face ofthe frame 16.

A sealing ring 38' rests upon a shoulder 39 formed within the projection25 at the entrance to the opening 38. The ring 38' is secured firmly inposition by means of a ring stake on the shoulder 36 and closelysurrounds the stem 33 of push button 24. By ring staking the sealingring 38' in position, the ring 3% cannot be displaced duringreciprocation of the push button.

In certain installations wherein push button switch stations areemployed, it is desirable to make provision for locking a switch in aselected operating condition and at the same time to prevent depressionof the push button for changing the switch-operating condition. By wayof example, in the control of punch presses, a number of push buttonswitch actuators are utilized as run buttons each to control a pair ofswitches, such as the switches 12 and 13, to simultaneously actuate anormally closed switch to an open condition and a normally open switchto a closed condition. In order to operate the press, it is necessarythat the plurality of push button actuators be depressed at the sametime by operating personnel. In such installations it is desirable tomake provisions for locking both the normally closed and normally openswitches in their closed operating conditions, and for preventingoperation of the normally closed switch to a normally open conditionafter the normally open switch is locked in its normally closedcondition.

In the present invention such a locking arrangement is provided by thelock means 15 which includes a lock member in the form of a plate 40positioned at the rear of the frame 16 and attached as by a screw 41 toa conventional key cylinder mechanism 42 rotatably mounted within ahollow projection 43 extending from the front of the frame 16 to effectrotation of the plate 40 about an axis generally parallel to the axis ofreciprocation of the push button. The plate 49 is rotated between aninactive position and a locking position in response to turning of a key44 which is inserted into the mechanism 42. A sealing ring 45 bearsagainst a shoulder formed within the projection 43 to closely surroundthe reduced end 45' of the mechanism 42.

The lock means 15 is effective to operate the switch 13 from itsnormally open condition to its closed condition during rotation of thelock means from its inactive position to its locking position. For thispurpose the plate 46) includes a cam portion 4-6 which engages theoperating element 21 during rotation of the plate 44 to its lockingposition and cams the element 21 inwardly of the casing of the switch13. When the plate 40 is in its locking position, the lower surface ofthe plate at} as viewed in FIG. 4 engages the element 21 and holds suchelement in its inward position to establish a normally closed conditionof the switch 13.

Another function of the lock means 15 is to prevent depression of thepush button 24 and thereby prevent operation of the switch 12 to itsopen condition after the switch 13 has been actuated to and locked inits closed condition. To this end the plate it} includes a projection4-7 which when the plate 4% is in its locking position, projects towardand confronts the switch actuating plate 23 to prevent substantialmovement thereof toward the operating element 20. In FIGS. 2 and 3 theplate 40 is shown in its inactive position, and in FIG. 4 the plate 40is shown in its locking position wherein it maintains the switch 13 in aclosed condition.

A sealing ring 49 of generally rectangular configuration fits snuglyWithin a correspondingly shaped groove 50 formed in the rear face of theframe 16 adjacent the periphery thereof. The depth of the groove 50 isless than the thickness of the ring 49 so that a portion of thethickness of the ring 49 projects outwardly from the rear face of theframe. When the frame 16 is secured to the panel 11, the ring 49 iscompressed almost flush with the rear face of the frame to provide avery effective seal.

While we have shown and described a particular embodiment of ourinvention, it will be obvious to those skilled in the art that variouschanges and modifications may be made without departing from ourinvention in its broader aspects and we, therefore, intend in theappended claims to cover all such changes and modifications as fallWithin the true spirit and scope of our invention.

hat we claim as new and desired to secure by Letters Patent of theUnited States is:

l. A switch device comprising support means, a pair of switches mountedon said support means each having an operating element displaceablebetween first and second positions, said operating elements normallybeing in said first positions to establish preselected switch operatingconditions and being displaceable to said second positions to establishother switch operating conditions, a switch actuator mounted on saidsupport means for movement relative thereto to simultaneously displacesaid operating elements between said first and second positions, andkey-operated locking means mounted on said support means including alocking member mounted for rotation relative to said support meansbetween inactive and locking positions about an axis generally parallelto the direction of movement of said switch actuator, said lockingmember extending generally perpendicular to its axis of rotation, saidlocking member having a first part which during movement of the lockingmember to the locking position operates to displace a single one of saidoperating elements to its second position, said locking member when inits locking position engaging and holding said one operating element inits second position, said locking member having a second part whichconfronts the switch actuator when the locking member is in its lockingposition to prevent movement of the switch actuator in a direction fordisplacing said operating elements.

2. A device as defined in claim 1 wherein said one operating elementwhen in said first position establishes a normally open condition of itsswitch, the other operating element when in said first positionestablishing a normally closed condition of its switch.

3. A switch device comprising support means, a pair of switches mountedon said support means each having an operating element displaceablebetwen first and second positions, said operating elements normallybeing in said first positions to establish preselected switch operatingconditions and being displaceable along spaced parallel first axes tosaid second positions to establish other switch operating conditions, aswitch actuator mounted on said support means and including an actuatingmember mounted for reciprocation relative to said support means along asecond axis parallel to said first axes to substantially simultaneouslydisplace said operating elements between said first and secondpositions, and a key-operated locking member having a cam portion and aprojection and being mounted by said support means for rotation relativeto the support means about an axis generally parallel to the directionof reciprocation of said actuating member between inactive and lockingpositions, said locking member extending generally perpendicular to itsaxis of rotation, said locking member during rotation toward its lockingposition moving the cam portion to displace a single one of saidoperating elements to its second position, said locking member when inits locking position holding said one operating element in its secondposition and also locating said projection in confronting relation withsaid actuating member to prevent movement of the actuating member in adirection for displacing said operating elements.

4. A device as defined in claim 3 wherein said one operating elementwhen in said first position establishes a normally open condition of itsswitch, the other operating element when in said first positionestablishing a normally closed condition of its switch.

5. A switch device comprising a supporting frame, a pair of switchesmounted on one side of said frame, each of said switches having anoperating element displaceable between first and second positions, saidoperating elements normally being in said first positions to establishpreselected switch operating conditions and being displaceable alongspaced parallel first axes to said second positions to establish otherswitch operating conditions, a switch actuator mounted on said frameoperable from the other side of said frame and including an actuatingplate on said one side of the frame, said plate being reciprocablerelative to said frame along a second axis perpendicular to its planeand parallel to said first axes to substantially simultaneously displacesaid operating elements between said first and second positions, andlocking means mounted on said frame key-operated from said other side ofsaid frame and having a locking member on said one side of the framemovable relative to said frame to a locking position, said lockingmember having a cam part which during movement of the locking member toits locking position displaces a single one of said operating elementsto its second position, said locking member when in its locking positionengaging and holding said one operating element in its second position,said locking member having a projection which is positioned inconfronting relation with said actuating plate when the locking memberis in its locking position to prevent movement of said plate towardssaid operating elements.

6. A switch device comprising a supporting frame, a pair of switchesmounted on one side of said frame,

each of said switches having an operating element displaceable betweenfirst and second positions, said operating elements normally being insaid first positions to establish preselected switch operatingconditions and being displaceable along spaced parallel first axes tosaid second positions to establish other switch operating conditions, aswitch actuator mounted on said frame operable from the other side ofsaid frame and including an actuating plate on said one side of theframe, said plate being reciprocable relative to said frame along asecond axis perpendicular to its plane and parallel to said first axesto substantially simultaneously displace said operating elements betweensaid first and second positions, and locking means mounted on said framekey-operated from said other side of said frame including a lockingmember .on said one side of the frame having a cam portion and aprojection, said locking member being mounted for rotation relative tosaid frame about an axis generally parallel to the direction ofreciprocation of said plate between inactive and locking positions, saidlocking member extending generally perpendicular to its axis ofrotation, said locking member during rotation toward its lockingposition moving the cam portion to displace a single one of saidoperating elements to its second position, said locking member when inits locking position holding said one operating element in its secondposition and also locating said projection in confronting relation withsaid plate to prevent movement of the plate in a direction fordisplacing said operating elements.

7. A switch device comprising a supporting frame, a pair of switchesmounted on one side of said frame, each of said switches having anoperating element displaceable between first and second positions, saidoperating elements normally being in said first positions to establishpreselected switch operating conditions and being displaceable alongspaced parallel first axes to said second positions to establish otherswitch operating conditions, a switch actuator mounted on said frameoperable from the other side of said frame and including an actuatingplate on said one side of the frame, said plate being reciprocablerelative to said frame along a second axis perpendicular to its planeand parallel to said first axes to substantially simultaneously displacesaid operating elements between said first and second position, andlooking means mounted on said frame key-operated from said other side ofsaid frame including a locking member on said one side of the framehaving a cam portion and a projection, said locking member being mountedfor rotation relative to said frame about an axis generally parallel tothe direction of reciprocation of said plate between inactive andlocking positions, said locking member extending generally perpendicularto its axis of rotation said locking member during rotation toward itslock ing position moving the cam portion to displace a single one ofsaid operating elements to its second position, said locking member whenin its locking position holding said one operating element in its secondposition and also locating said projection in confronting relation withsaid plate to prevent movement of the plate in a direction fordisplacing said operating elements, said frame hav ing a slot opening atsaid one side thereof, said plate having a part extending into said slotto prevent rotation of the plate during reciprocation thereof.

8. A switch device comprising a supporting frame, a pair of switcheseach having an operating element displaceable between first and secondpositions, a support plate mounted by said frame on one side thereof,said switches being secured to said support plate in side by siderelation with their operating elements extending toward said frame, saidoperating elements normally being in said first positions to establishpreselected switch operating conditions and being displaceable alongspaced parallel first axes to said second positions to establish otherswitch operating conditions, a switch actuator operable from the otherside of said frame and being spring biased away from said frame, saidactuator including an actuating plate on said one side of the frame,said operating elements being spaced from said actuating plate bysubstantially equal distances, said actuating plate being reciprocablealong a second axis perpendicular to its plane and parallel to saidfirst axes to substantially simultaneously displace said operatingelements between said first and second positions, and locking means keyoperated from said other side of said frame including a key cylindermechanism extending through said frame to said one side thereof, and anelongated locking member secured at one of its ends to said mechanism onsaid one side of the frame to extend generally perpendicular to saidsecond axis, said locking member having adjacent its other end a camportion and a projection, said locking member being rotatable about anaxis generally parallel to said second axis between inactive and lockingpositions in response to rotation of said mechanism, said locking memberduring rotation toward its locking position moving its cam portion todisplace a single one of said operating elements to its second position,said locking member when in its locking position holding said oneoperating element in its second position and also locating saidprojection in confronting relation with said actuating plate to preventmovement of the actuating plate in a direction for displacing saidoperating elements, said frame having a slot opening at said one sidethereof, said actuating plate having a part extending into said slot toprevent rotation of the actuating plate during reciprocation thereof.

References Cited by the Examiner UNITED STATES PATENTS 2,680,368 6/54McKitrick 200-44 2,896,034 7/59 Nolden et al 200-18 3,056,481 10/62Luenser 200-44 3,104,687 9/63 Field 200-44 X BERNARD A. GILHEANY,Primary Examiner.

ROBERT K. SCHAEFER, Examiner.

1. A SWITCH DEVICE COMPRISING SUPPORT MEANS, A PAIR OF SWITCHES MOUNTEDON SAID SUPPORT MEANS EACH HAVING AN OPERATING ELEMENT DISPLACEABLEBETWEEN FIRST AND SECOND POSITION, SAID OPERATING ELEMENTS NORMALLYBEING IN SAID FIRST POSITIONS TO ESTABLISH PRESELECTED SWITCH OPERATINGCONDITIONS AND BEING DISPLACEABLE TO SAID SECOND POSITIONS TO ESTABLISHOTHER SWITCH OPERATING CONDITIONS, A SWITCH ACTUATOR MOUNTED ON SAIDSUPPORT MEANS FOR MOVEMENT RELATIVE THERETO TO SIMULTANEOUSLY DISPLACESAID OPERATING ELEMENTS BETWEEN SAID FIRST AND SECOND POSITIONS, ANDKEY-OPERATED LOCKING MEANS MOUNTED ON SAID SUPPORT MEANS INCLUDING ALOCKING MEMBER MOUNTED FOR ROTATION RELATIVE TO SAID SUPPORT MEANSBETWEEN INACTIVE AND LOCKING POSITIONS ABOUT AN AXIS GENERALLY PARALLELTO THE DIRECTION OF MOVEMENT OF SAID SWITCH ACTUATOR, SAID LOCKINGMEMBER EXTENDING GENERALLY PERPENDICULAR TO ITS AXIS OF ROTATION, SAIDLOCKING MEMBER HAVING A FIRST PART WHICH DURING MOVEMENT OF THE LOCKINGMEMBER TO THE LOCKING POSITION OPERATES TO DISPLACE A SINGLE ONE OF SAIDOPERATING ELEMENTS TO ITS SECOND POSITION, SAID LOCKING MEMBER WHEN INITS LOCKING POSITION ENGAGING AND HOLDING SAID ONE OPERATING ELEMENT INITS SECOND POSITION, SAID LOCKING MEMBER HAVING A SECOND PART WHICHCONFRONTS THE SWITCH ACTUATOR WHEN THE LOCKING MEMBER IS IN ITS LOCKINGPOSITION TO PREVENT MOVEMENT OF THE SWICH ACTUATOR IN A DIRECTION FORDISPLACING SAID OPERATING ELEMENTS.